1. Field of the Invention
Fires are frequently started by children playing with disposable cigarette lighters. The U.S. Consumer Product Safety Commission (the "CPSC") has moved to require such lighters to be made child-resistant. A common form of disposable lighter includes a main body portion defining a fuel reservoir that contains a combustible fluid under pressure, an upper end portion mounted on the main body portion on which upper end portion a valve mechanism is mounted communicating with the fuel reservoir, and a lever pivotally mounted on the upper end portion having one end engaged with the valve mechanism and an opposite end defining a pushbutton that is normally spaced apart from but depressible by thumb toward a top wall of the upper end portion for operating the valve mechanism from a normally closed condition that prevents release of fuel to an open condition that permits release of fuel, the pushbutton being depressible against the resistance of a spring whereby the pushbutton is biased to return its normal position spaced apart from the said top wall. In a form of disposable lighter to which the present improvement is applicable, the pushbutton biasing spring is incorporated in the valve mechanism where it biases a nozzle element thereof downwardly into a valve closure position and thereby simultaneously biases the pushbutton upwardly. Depression of the pushbutton lifts the nozzle to an open position whereby fuel is released in a gaseous state. Simultaneously with depression of the pushbutton, the user rolls a flintwheel that is mounted on the lighter's upper end portion over the pivotal axis of the lever, rotation of the flintwheel abrading a flint that generates sparks that ignite the released combustible gas. When the user releases the pushbutton, the pushbutton and the nozzle element return to their respective initial positions.
It has frequently been proposed to make such a lighter child resistant by adding an element that, when in a given initial position, prevents depression of the pushbutton whereby the valve mechanism normally cannot be operated to its open position, but which element, when operated to a given alternate position permits depression of the pushbutton, and further functions such that, after depression and release of the pushbutton, the said element automatically returns the pushbutton to its normally locked condition. The invention pertains to an improvement in such means.
2. Description of Prior Art
Disposable lighters are assembled at high speed by automatically operating machinery that is specialized to handle a lighter of given external size and shape. A child-resistant lighter concept that differs so radically from the current product of a given manufacturer that it would require major alteration of existing facilities is not economically feasible. Accordingly, in order that existing facilities can be utilized, it is necessary to, in effect, convert the current lighter product into one that is child-resistant, as opposed to creating a wholly new product.
Producibility by existing facilities requires that, externally, the main body portion of the child-resistant version remain unchanged from that of the current product; i.e., modifications necessary to make the conventional product child-resistant must be confined to its upper end portion.
A further constraint is that current fuel capacity must not be reduced and this precludes the arrangement of any child-resistance-effecting structure inside the main body portion of the conventional lighter where it would reduce the volume of the fuel reservoir.
Still another consideration is that, since assembly of a disposable lighter is by machine involving machine movements that sequentially snap into place all components of the lighter at extremely high speed, the structure effecting child-resistancy must be of such nature as to lend itself to handling by such machinery for such mode of assembly.
Finally, economy is critical since the lighter is intended to be disposable.
A number of child-resistant lighters have previously been proposed but only a very few have met all of the requirements listed above.
At present, the only technical requirements mandated by the CPSC with respect to the nature of the child-resistance-effecting mechanism per se are that the lighter must be operable by an adult using only one hand (in order not to introduce a new hazard; e.g. when driving a vehicle) and that the lighter's valve-actuating pushbutton must automatically be returned to its normally locked condition after each depression and release (as opposed to requiring the user to manually reset the locking device).
Child-resistant lighters meeting these CPSC mandated requirements must also qualify under a performance test protocol involving a panel of children less than five years old, an age group determined to be most often involved in fires caused by children playing with disposable lighters, children at ages three and four having been determined to be the critical age group.
As this is written, 85% of a given panel of children must be unable to successfully operate a surrogate child-resistant lighter (emitting a signal instead of producing a flame) within a given test period. The test protocol provides for one or more demonstrations of such surrogate child-resistant lighter by the tester in order to reflect real-life situations wherein the child may observe an adult using the actual child-resistant lighter.
The Federal Register, Vol. 57, No. 159, Aug. 17, 1992, pages 36932-64 entitled "Proposed Safety Standard for Cigarette Lighters" (the "Standard") provides a comprehensive discourse of the development of a child-resistant lighter safety standard.
On page 36934 of the above-referenced issue of the Federal Register it is reported that studies "suggest that the child-resistance of currently marketed lighters is approximately 50%" and that (referring to the 85% qualification test protocol) "This constitutes at least a 70% improvement over the existing degree of child-resistance . . . "
On page 36933 of the above-referenced issue of the Federal Register it is stated with reference to studies of how children manipulate a disposable lighter:
"The most common method of operation by children was with two hands, using one hand to steady the lighter and the thumb or index finger of the other hand to roll the wheel and press the fuel lever."
Although children thereby have a manipulative advantage over the one-handed operation characteristic of adults, to date there is no requirement that the device relied upon in a child-resistant lighter to maintain its valve-actuating pushbutton normally locked against depression shall require prerequisite operation in more than one direction in order to render the pushbutton depressible. However, several child-resistant lighters having a locking member that need be operated in only a single direction in order to render the pushbutton depressible are known to have met or exceeded the 85% qualification test and, accordingly, are permissible to market.
Given that children in the critical age group characteristically use both hands to operate a lighter, there would appear to be nothing intrinsic in a child-resistant lighter having a "single-action" locking member that would prevent a child from either deliberately or accidentally moving the locking member, by a simple straight-line movement, into its pushbutton unlocking position, even in the case of a child-resistant lighter having a locking member that would have to be positively held in its unlocked position, since the hand that is being used to steady the lighter can be used for that purpose while the other hand presses the pushbutton. Any single-action device is subject to early defeat since children at ages three and four characteristically probe, push and pull various parts of a new toy to see what works what.
Clearly, since a single-action locking member needs to be pushed in only one direction and it will unlock the pushbutton, such a device relies wholly on the child not pushing the locking member. No parent requires proof that children ages three and four are characterized by curiosity and physical activity. Since curiosity and physical effort are all that a single-action child-resistant lighter requires of a child in order to render the pushbutton depressible, both of which qualities children in the critical age group have in abundance, a single-action device offers the lowest possible level of safety.
Approximately 500 million disposable lighters are sold each year in the United States, creating millions of opportunities each year for the correct combination of circumstances to exist wherein the child pushes the locking member in its single direction and also depresses the pushbutton (possibly also rolling the flintwheel). In light of the large numbers involved, a certain number of fatalities and serious burn injuries may occur that could have been avoided by a child-resistant lighter that required children to apply conceptual or keen observational skills--abilities not typical of children ages three and four. Of course, mere random effort, especially if the child is persistent, will, in light of such a large number of exposures each year, inevitably result in a number of defeats of any child-resistant lighter no matter how subtle or complex its mode of operation. But it seems reasonable to assume that the more that a child has to do in order to render the pushbutton depressible, the fewer the number of children that will be able to do it.
Accordingly, it would seem that a child-resistant lighter should be required to have a locking member that must necessarily be moved in at least two different directions before the pushbutton will be rendered depressible, in order to minimize the likelihood of accidental successful operation by children in the critical age group. The movement of the locking member that renders the pushbutton depressible is generally difficult to conceal. But a locking member requiring an additional movement as a prerequisite to the movement that actually unlocks the pushbutton provides an opportunity for such additional movement to be so much more subtle as not to be easily observable by children. Where such a double-action feature can be incorporated without added manufacturing expense, with the same ease of manufacture, and without significantly adding to adult inconvenience, there is little justification for not providing children such added measure of safety.
A goal of this invention is to effect child-resistance in a conventional disposable lighter product, within the context of satisfaction of all of the requirements described above pertaining to practical and economical producibility, by adding to the current lighter product only a single element that can be plugged into the suitably prepared current lighter product, and which single element is of such nature that, in preferred embodiment, it requires its actuator portion to necessarily be moved in two different directions in order to render the pushbutton depressible, but which single element, given the circumstance that the safety standard presently proposed does not mandate such a double-action mode of operation, readily lends itself to provision in alternative form not having such extra feature, in order that a manufacturer operating under benefit of the instant disclosure shall have the option, if deemed necessary or desirable in light of competitive expediency, to, at least initially, offer a product not exceeding the difficulty of operation of competing products.
Morris, Sr., U.S. Pat. No. 4,832,596, discloses a single-action device wherein a rigid stop member is mounted so as to be slidable straight under the lighter's pushbutton. In each of several embodiments the stop member has an initial position that normally blocks depression of the pushbutton and is movable, against the resistance of a distinct spring or compressible rubber piece, to an alternate position that permits depression of the pushbutton, such movement being effected by application of the index finger to an actuator portion located adjacent the front end of the lighter body (nearest where the flame is produced) and being pulled or squeezed toward the lighter body to slide a blocking portion of the stop member out of a blocking position under the pushbutton. One embodiment discloses a stop member having a portion thereof that is planar and slidable on a top wall of the lighter's upper end portion under its pushbutton, but is limited in that such planar portion is part of a considerably larger structure that is arranged externally of the lighter body. An advantage characterizing all embodiments is that the actuator portion of the pushbutton-locking structure must be positively held by the user in its pushbutton-unlocking position with the index finger of one hand while the thumb of that hand is depressing the pushbutton; i.e., nothing mechanically holds the device in its unlocked position once operated, and accordingly, such a child-resistant lighter inherently cannot be left lying about in an unlocked condition. But in all embodiments the bulkiness and arrangement of the elements is such that a child could not help but become curious, and in any event, producibility according to conventional practice would be at least difficult.
Although the accompanying drawings illustrate the preferred embodiment of the invention pushbutton-locking spring wherein the user must necessarily effect a double-action mode of operation (the actuator being then positively held in its unlocked position by mechanical means), a single-action alternative embodiment is anticipated wherein the user must manually hold the actuator at its inwardly pushed position while depressing the pushbutton; i.e., an alternative embodiment operable in the manner of the Morris, Sr. embodiments except performed at the pushbutton end of the lighter body. Such an alternative embodiment need not utilize the third arm member of the preferred embodiment but may have its actuator proportioned large enough so that it can be squeezed inwardly using the root portion of the index finger or adjacent portion of the palm of one hand while using the thumb of the same hand to depress the lighter's pushbutton. However, such an alternative embodiment would require its actuator to normally project further outwardly of the lighter's upper end portion (increasing bulkiness and notice) and, for acceptably comfortable adult usage, may have its actuator extending downwardly toward the main body portion, possibly adversely impacting producibility by existing facilities and making operation by children easier. Further, the outward projection and downward extension of such an actuator portion would effectively define a hook that becomes an annoyance when one attempts to drop the lighter into a pocket. On the other hand, such an alternative embodiment does have the significant advantage that the adult user cannot leave it lying about in an unlocked condition. It is therefore hereby expressly anticipated and included within the intended scope of the appended claims, but in view of the described limitations, such an alternative embodiment is not advocated and not illustrated in the accompanying drawings.
Fairbanks, et al., U.S. Pat. No. 5,002,482 (assignee BIC Corporation) discloses an effectively single-action device wherein a resilient stop member is mounted on the lighter's upper end portion under its pushbutton to normally block the pushbutton against depression, the stop member having an actuator portion thereof that projects outwardly of the lighter's upper end portion immediately adjacent its pushbutton and is movable arcuately sideways (by compression of a resilient portion of the stop member) and then upwardly so that it assumes a position in frictional engagement with an adjacent side of the pushbutton. When the pushbutton is depressed and then released the actuator moves downwardly and sideways back under the pushbutton. Multiple-step mode of operation is asserted on the basis that the actuator must be thus moved in two different directions. In point of fact the pushbutton is rendered depressible when the actuator is moved only sideways. A child need therefore move the actuator in only one direction and he will be able to depress the pushbutton, provided of course that the child is manually holding the actuator in such sideways moved position. The upward movement is provided for the convenience of the adult user. In order that the adult user can operate the lighter using only one hand he must remove his thumb from the actuator and apply it to the pushbutton for depression of it. This requires that the actuator be positively held in its sideways moved position. The upward movement and placement of the actuator adjacent the pushbutton serves that purpose.
Fujita, U.S. Pat. No. 5,074,781 (assignee Pollyflame Japan, Ltd.) is a single-action device wherein a rigid stop member is rotatably mounted on the lighter's upper end portion under its pushbutton and cooperates with a distinct coil spring that is mounted in compression under the stop member in an arrangement that eliminates the need for a child to manually hold the actuator sideways. In the Fujita improvement the coil spring impels the actuator upwardly to a pushbutton-unlocking position the moment the child pushes the actuator sideways. Fujita thereby offers a child-resistant lighter wherein the child does not have to hold the actuator sideways and does not have to push it upwardly--Fujita's improvement performs both functions for the child automatically.
Floriot, U.S. Pat. No. 5,090,893 (assignee Cricket) discloses several embodiments, some of which involve arcuate movement of an actuator and others of which involve straight-line movement of an actuator, but all of which are single-action devices. As in Fujita, in each the Floriot embodiments, when the actuator is moved in a single direction the actuator is positively held in its pushbutton-unlocking position by mechanical means until such time as the pushbutton is depressed and released.
As indicated above, the Standard seeks only to raise the level of child-resistancy from the 50% attained by the currently marketed product to 85% (which the CPSC has calculated to be only a 70% improvement), as opposed to requiring the industry to produce the most child-resistant lighter that it is technically possible to produce within the constraints of economy and adult convenience. In other words the Standard as presently written is "performance driven" and does not necessarily reflect the presently known state of the art (at least as evidenced by submissions (not including the patent next cited) by this inventor to the CPSC). So long as a given product meets the passively locking requirement and 85% qualification, it is marketable even though a product that might obtain a greater than 70% improvement could just as economically have been marketed having negligible adverse effect on consumer acceptance. In light of such permissiveness of the present Standard, an alternative embodiment of the invention pushbutton-locking spring is illustrated in the accompanying drawings having a single-action mode of operation competitive with that of the art described above.
Cirami, U.S. Pat. No. 4,830,603, is the only issued patent known to disclose a child-resistant lighter wherein the actuator portion of a pushbutton locking member must necessarily be moved in two different directions in order to render the lighter's pushbutton depressible. It discloses a U-shaped spring but of such size and arrangement as to adversely impact producibility of such a lighter. Such a U-shaped spring neither anticipates nor makes obvious the invention pushbutton-locking spring which has one portion thereof that is U-shaped and mounted in a recess that is restricted to the lighter's upper end portion and another portion thereof defining a stop member that is contiguous with a first arm member of the U-shaped portion and extends therefrom so as to be slidably mounted on the top wall of the lighter's upper end portion; neither does such patent suggest a mode of operation wherein by pushing an actuator formed at one end of the stop member, the stop member is moved from a given initial position to a given alternate position by forcing such first arm member to flex toward a second arm member of the U-shaped portion whereby the stop member is biased to return to its initial position.
The art discussed above is believed to be the closest and no more pertinent art is known to bear on the present subject matter.